Commit Graph

180 Commits

Author SHA1 Message Date
Gustavo F. Padovan 4e34c50bfe Bluetooth: move l2cap_sock_connect() to l2cap_sock.c
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:43:31 -02:00
Gustavo F. Padovan 99f4808db0 Bluetooth: move l2cap_sock_getsockopt() to l2cap_sock.c
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:43:31 -02:00
Gustavo F. Padovan 33575df7be Bluetooth: move l2cap_sock_setsockopt() to l2cap_sock.c
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:43:31 -02:00
Gustavo F. Padovan d7175d5525 Bluetooth: move l2cap_sock_getname() to l2cap_sock.c
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:43:30 -02:00
Gustavo F. Padovan c47b7c724b Bluetooth: move l2cap_sock_accept() to l2cap_sock.c
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:43:30 -02:00
Gustavo F. Padovan af6bcd8205 Bluetooth: move l2cap_sock_bind()/listen() to l2cap_sock.c
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:43:30 -02:00
Gustavo F. Padovan 554f05bb8a Bluetooth: move l2cap_sock_release() to l2cap_sock.c
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:43:30 -02:00
Gustavo F. Padovan 65390587c7 Bluetooth: move l2cap_sock_ops to l2cap_sock.c
First step to move all l2cap_sock_ops function to l2cap_sock.c

Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:43:30 -02:00
Gustavo F. Padovan bb58f747e5 Bluetooth: Initial work for L2CAP split.
This patch tries to do the minimal to move l2cap_sock_create() and its
dependencies to l2cap_sock.c. It create a API to initialize and cleanup
the L2CAP sockets from l2cap_core.c through l2cap_init_sockets() and
l2cap_cleanup_sockets().

Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:43:30 -02:00
Johan Hedberg 17fa4b9dff Bluetooth: Add set_io_capability management command
This patch adds a new set_io_capability management command which is used
to set the IO capability for Secure Simple Pairing (SSP) as well as the
Security Manager Protocol (SMP). The value is per hci_dev and each
hci_conn object inherits it upon creation.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:08 -02:00
Johan Hedberg 980e1a537f Bluetooth: Add support for PIN code handling in the management interface
This patch adds the necessary commands and events needed to communicate
PIN code related actions between the kernel and userspace. This includes
a pin_code_request event as well as pin_code_reply and
pin_code_negative_reply commands.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:07 -02:00
Johan Hedberg 2784eb41b1 Bluetooth: Add get_connections managment interface command
This patch adds a get_connections command to the management interface.
With this command userspace can get the current list of connected
devices. Typically this command would only be used once when enumerating
existing adapters. After that the connected and disconnected events are
used to track connections.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:07 -02:00
Johan Hedberg 17d5c04cb5 Bluetooth: Add support for connect failed management event
This patch add a new connect failed management event to track failures
in connecting to remote devices. It is particularly useful for security
mode 3 scenarios when we don't have a connected state while pairing but
still need to detect when the connect attempt failed.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:07 -02:00
Johan Hedberg 8962ee74be Bluetooth: Add disconnect managment command
This patch adds a disconnect command to the managment interface. Using
this command user space is able to force the disconnection of connected
devices. The command maps directly to the Disconnect HCI command.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:07 -02:00
Johan Hedberg f7520543ab Bluetooth: Add connected/disconnected management events
This patch adds connected and disconnected managment events to track the
connection status to remote devices. The events map directly to
successful connection complete and disconnection complete HCI events for
ACL links.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:07 -02:00
Johan Hedberg 55ed8ca10f Bluetooth: Implement link key handling for the management interface
This patch adds a management commands to feed the kernel with all stored
link keys as well as remove specific ones or all of them. Once the
load_keys command has been called the kernel takes over link key
replies. A new_key event is also added to inform userspace of newly
created link keys that should be stored permanently.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:07 -02:00
Johan Hedberg 1aff6f0949 Bluetooth: Add class of device control to the management interface
This patch adds the possibility for user space to fully control the
Class of Device value of local adapters. To control the service class
bits each UUID that's added comes with a service class "hint" which acts
as a mask of bits that the UUID needs to have enabled. The
set_service_cache management command is used to make sure we queue up
all UUID changes as user space initializes its drivers and then send a
single HCI_Write_Class_of_Device command when initialization is
complete.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:06 -02:00
Johan Hedberg d5859e22cd Bluetooth: Implement a more complete adapter initialization sequence
Using the managment interface means that user space doesn't need to do
any HCI command sending at all. This patch moves the remaining
initialization commands from user space to the kernel side. The patch
makes use of the new feature of __hci_request which allows the request
to be dynamically modified while it is ongoing (something that is needed
to react appropriately to the local features and the version of the
adapter).

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:06 -02:00
Johan Hedberg b0916ea0d9 Bluetooth: Add controller side link key clearing to hci_init_req
The controller may have link keys in its own memory and these keys could
be used for secure connections. However, since the interface to access
these keys doesn't provide information about the key types (which would
be needed to infer the level of security each key provides) using these
keys is rather useless. Therefore, simply clear the controller side list
in the initialization procedure.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:06 -02:00
Johan Hedberg a5040efa20 Bluetooth: Add special handling with __hci_request and HCI_INIT
To support a more dynamic HCI initialization sequence the __hci_request
behavior requires some more changes. Particularly, the init sequence
should be able to have conditionals in it (sending some HCI commands
depending on the outcome of a previous command) instead of being a fixed
list as it is right now.

The reasons for these additional requirements are the moving all
previously user space driven initialization commands to the kernel side
as well as the support the Low Energy controllers.

To fulfull these requirements the init sequence is made the only special
case for multi-command requests and req_last_cmd is renamed to
init_last_cmd. The hci_send_cmd function is changed to update
init_last_cmd as long as the HCI_INIT flag is set.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:06 -02:00
Johan Hedberg 03b555e119 Bluetooth: Reject pairing requests when in non-pairable mode
This patch adds the necessary logic to act accordingly when the
HCI_PAIRABLE flag is not set. In that case PIN code replies as well as
Secure Simple Pairing requests without a NoBonding requirement need to
be rejected.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:06 -02:00
Johan Hedberg 2aeb9a1ae0 Bluetooth: Implement UUID handling through the management interface
This patch adds methods to the management interface for userspace to
notify the kernel of which services have been registered for specific
adapters. This information is needed for setting the appropriate Class
of Device value as well as the Extended Inquiry Response value. This
patch doesn't actually implement setting of these values but just
provides the storage of the UUIDs so the needed functionality can be
built on top of it.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:05 -02:00
Johan Hedberg c542a06c29 Bluetooth: Implement set_pairable managment command
This patch implements a new set_pairable management command to control
the pairable state of local adapters. The state is represented using a
new HCI_PAIRABLE flag in the hci_dev struct.

For backwards compatibility with older user space versions the
HCI_PAIRABLE flag gets automatically set when the existence of an
adapter is reported to user space through legacy methods and the
HCI_MGMT flag is not set.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:05 -02:00
Johan Hedberg ebc99feba7 Bluetooth: Add flag to track managment controlled adapters
This patch adds a HCI_MGMT flag to track adapters which are under the
control of the management interface. This is needed to make sure that
new kernels will work with old user space versions. I.e. behaviour which
could break old user space versions (but is needed by the management
interface) should not be exhibited when the HCI_MGMT flag is not set.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:05 -02:00
Johan Hedberg 72a734ec1a Bluetooth: Unify mode related management messages to a single struct
The powered, connectable and discoverable messages all have the same
format. By using a single struct for all of them a lot of code can be
simplified and reused.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:05 -02:00
Johan Hedberg 9fbcbb455d Bluetooth: Add set_connectable management command
This patch adds a set_connectable command as well as a corresponding
event to the management interface. It's mainly useful for setting an
adapter as connectable from a non-initialized state as well as setting
an already initialized adapter as non-connectable (mostly useful for
qualification purposes).

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:05 -02:00
Johan Hedberg 73f22f6238 Bluetooth: Add support for set_discoverable management command
This patch adds a set_discoverable command to the management interface
as well as the corresponding event. The command is used to control the
discoverable state of adapters.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:04 -02:00
Johan Hedberg eec8d2bcc8 Bluetooth: Add support for set_powered management command
This patch adds a set_powered command to the management interface
through which the powered state of local adapters can be controlled.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:04 -02:00
Johan Hedberg 5add6af8fc Bluetooth: Add support for management powered event
This patch adds support for the powered event that's used to indicate to
userspace when the powered state of a local adapter changes.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:04 -02:00
Johan Hedberg ab81cbf99c Bluetooth: Implement automatic setup procedure for local adapters
This patch implements automatic initialization of basic information
about newly registered Bluetooth adapters. E.g. the address and features
are always needed so it makes sense for the kernel to automatically
power on adapters and read this information. A new HCI_SETUP flag is
added to track this state.

In order to not consume unnecessary amounts of power if there isn't a
user space available that could switch the adapter back off, a timer is
added to do this automatically as long as no Bluetooth user space seems
to be present. A new HCI_AUTO_OFF flag is added that user space needs to
clear to avoid the automatic power off.

Additionally, the management interface index_added event is moved to the
end of the HCI_SETUP stage so a user space supporting the managment
inteface has all the necessary information available for fetching when
it gets notified of a new adapter. The HCI_DEV_REG event is kept in the
same place as before since existing HCI raw socket based user space
versions depend on seeing the kernels initialization sequence
(hci_init_req) to determine when the adapter is ready for use.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:04 -02:00
Andrei Emeltchenko e702112ff6 Bluetooth: Use non-flushable by default L2CAP data packets
Modification of Nick Pelly <npelly@google.com> patch.

With Bluetooth 2.1 ACL packets can be flushable or non-flushable. This commit
makes ACL data packets non-flushable by default on compatible chipsets, and
adds the BT_FLUSHABLE socket option to explicitly request flushable ACL
data packets for a given L2CAP socket. This is useful for A2DP data which can
be safely discarded if it can not be delivered within a short time (while
other ACL data should not be discarded).

Note that making ACL data flushable has no effect unless the automatic flush
timeout for that ACL link is changed from its default of 0 (infinite).

Default packet types (for compatible chipsets):
Frame 34: 13 bytes on wire (104 bits), 13 bytes captured (104 bits)
Bluetooth HCI H4
Bluetooth HCI ACL Packet
    .... 0000 0000 0010 = Connection Handle: 0x0002
    ..00 .... .... .... = PB Flag: First Non-automatically Flushable Packet (0)
    00.. .... .... .... = BC Flag: Point-To-Point (0)
    Data Total Length: 8
Bluetooth L2CAP Packet

After setting BT_FLUSHABLE
(sock.setsockopt(274 /*SOL_BLUETOOTH*/, 8 /* BT_FLUSHABLE */, 1 /* flush */))
Frame 34: 13 bytes on wire (104 bits), 13 bytes captured (104 bits)
Bluetooth HCI H4
Bluetooth HCI ACL Packet
    .... 0000 0000 0010 = Connection Handle: 0x0002
    ..10 .... .... .... = PB Flag: First Automatically Flushable Packet (2)
    00.. .... .... .... = BC Flag: Point-To-Point (0)
    Data Total Length: 8
Bluetooth L2CAP Packet

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:04 -02:00
Johan Hedberg 765c2a964b Bluetooth: Fix race condition with conn->sec_level
The conn->sec_level value is supposed to represent the current level of
security that the connection has. However, by assigning to it before
requesting authentication it will have the wrong value during the
authentication procedure. To fix this a pending_sec_level variable is
added which is used to track the desired security level while making
sure that sec_level always represents the current level of security.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-01-19 14:43:11 -02:00
Johan Hedberg 23bb57633d Bluetooth: Fix __hci_request synchronization for hci_open_dev
The initialization function used by hci_open_dev (hci_init_req) sends
many different HCI commands. The __hci_request function should only
return when all of these commands have completed (or a timeout occurs).
Several of these commands cause hci_req_complete to be called which
causes __hci_request to return prematurely.

This patch fixes the issue by adding a new hdev->req_last_cmd variable
which is set during the initialization procedure. The hci_req_complete
function will no longer mark the request as complete until the command
matching hdev->req_last_cmd completes.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2010-12-22 22:58:07 -02:00
Johan Hedberg c71e97bfaa Bluetooth: Add management events for controller addition & removal
This patch adds Bluetooth Management interface events for controller
addition and removal. The events correspond to the existing HCI_DEV_REG
and HCI_DEV_UNREG stack internal events.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2010-12-22 22:58:00 -02:00
Johan Hedberg f7b64e69c7 Bluetooth: Add read_info management command
This patch implements the read_info command which is used to fetch basic
info about an adapter.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2010-12-22 22:57:51 -02:00
Johan Hedberg faba42eb2a Bluetooth: Add read_index_list management command
This patch implements the read_index_list command through which
userspace can get a list of current adapter indices.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2010-12-22 22:57:44 -02:00
Johan Hedberg 02d981292a Bluetooth: Add read_version management command
This patch implements the initial read_version command that userspace
will use before any other management interface operations.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2010-12-22 22:57:37 -02:00
Johan Hedberg a40c406cbd Bluetooth: Make hci_send_to_sock usable for management control sockets
In order to send data to management control sockets the function should:

  - skip checks intended for raw HCI data and stack internal events
  - make sure RAW HCI data or stack internal events don't go to
    management control sockets

In order to accomplish this the patch adds a new member to the bluetooth
skb private data to flag skb's that are destined for management control
sockets.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2010-12-07 23:03:39 -02:00
Johan Hedberg 0381101fd6 Bluetooth: Add initial Bluetooth Management interface callbacks
Add initial code for handling Bluetooth Management interface messages.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Andrei Emeltchenko <andrei.emeltchenko@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2010-12-07 23:03:38 -02:00
Johan Hedberg c02178d22b Bluetooth: Add Bluetooth Management interface definitions
Add initial definitions for the new Bluetooth Management interface to
the bluetooth headers.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2010-12-07 22:59:54 -02:00
Andrei Emeltchenko be21871f24 Bluetooth: clean up legal text
Remove extra spaces from legal text so that legal stuff looks
the same for all bluetooth code.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2010-12-01 21:04:43 -02:00
Andrei Emeltchenko 70f23020e6 Bluetooth: clean up hci code
Do not use assignment in IF condition, remove extra spaces,
fixing typos, simplify code.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2010-12-01 21:04:43 -02:00
Andrei Emeltchenko 894718a6be Bluetooth: clean up l2cap code
Do not initialize static vars to zero, macros with complex values
shall be enclosed with (), remove unneeded braces.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2010-12-01 21:04:43 -02:00
Andrei Emeltchenko 285b4e9031 Bluetooth: clean up rfcomm code
Remove extra spaces, assignments in if statement, zeroing static
variables, extra braces. Fix includes.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2010-12-01 21:04:43 -02:00
Andrei Emeltchenko 735cbc4784 Bluetooth: clean up sco code
Do not use assignments in IF condition, remove extra spaces

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2010-12-01 21:04:43 -02:00
Andrei Emeltchenko 534c92fde7 Bluetooth: clean up rfcomm code
Remove dead code and unused rfcomm thread events

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@nokia.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2010-10-12 12:44:53 -03:00
Mat Martineau 796c86eec8 Bluetooth: Add common code for stream-oriented recvmsg()
This commit adds a bt_sock_stream_recvmsg() function for use by any
Bluetooth code that uses SOCK_STREAM sockets.  This code is copied
from rfcomm_sock_recvmsg() with minimal modifications to remove
RFCOMM-specific functionality and improve readability.

L2CAP (with the SOCK_STREAM socket type) and RFCOMM have common needs
when it comes to reading data.  Proper stream read semantics require
that applications can read from a stream one byte at a time and not
lose any data.  The RFCOMM code already operated on and pulled data
from the underlying L2CAP socket, so very few changes were required to
make the code more generic for use with non-RFCOMM data over L2CAP.

Applications that need more awareness of L2CAP frame boundaries are
still free to use SOCK_SEQPACKET sockets, and may verify that they
connection did not fall back to basic mode by calling getsockopt().

Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2010-10-12 12:44:51 -03:00
David Vrabel 8f1e174223 Bluetooth: HCI devices are either BR/EDR or AMP radios
HCI transport drivers may not know what type of radio an AMP device has
so only say whether they're BR/EDR or AMP devices.

Signed-off-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2010-10-12 12:44:51 -03:00
David S. Miller d122179a3c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	net/core/ethtool.c
2010-10-11 12:30:34 -07:00
Gustavo F. Padovan e454c84464 Bluetooth: Fix deadlock in the ERTM logic
The Enhanced Retransmission Mode(ERTM) is a realiable mode of operation
of the Bluetooth L2CAP layer. Think on it like a simplified version of
TCP.
The problem we were facing here was a deadlock. ERTM uses a backlog
queue to queue incomimg packets while the user is helding the lock. At
some moment the sk_sndbuf can be exceeded and we can't alloc new skbs
then the code sleep with the lock to wait for memory, that stalls the
ERTM connection once we can't read the acknowledgements packets in the
backlog queue to free memory and make the allocation of outcoming skb
successful.

This patch actually affect all users of bt_skb_send_alloc(), i.e., all
L2CAP modes and SCO.

We are safe against socket states changes or channels deletion while the
we are sleeping wait memory. Checking for the sk->sk_err and
sk->sk_shutdown make the code safe, since any action that can leave the
socket or the channel in a not usable state set one of the struct
members at least. Then we can check both of them when getting the lock
again and return with the proper error if something unexpected happens.

Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: Ulisses Furquim <ulisses@profusion.mobi>
2010-09-30 12:19:35 -03:00